High-Performance Liquid Chromatographic Analysis of Triterpenoids in Commercial Frankincense

Abstract

A reversed-phase high-performance liquid chromatographic procedure has been developed: it is a simple and specific method for the determination of fifteen pentacyclic triterpenic compounds (a-boswellic acid, 3-O-acetyl-a-boswellic acid, b-boswellic acid, 3-O-acetyl-b-boswellic acid, a-amyrin, b-amyrin, lupeol, 3-epi-a-amyrin, 3-epi-b-amyrin, 3-epi-lupeol, a-amyrenone, b-amyrenone, lupenone, lupeolic acid and 3-O-acetyl-lupeolic acid) found in the most commonly traded frankincense, usually called ‘‘Eritrean-type’’ olibanum. In addition, the chromatographic comparison between fresh commercial resins and botanically certified ones was described in order to determine the geographical and/or the botanical origins of commercial frankincense. According to previous botanical studies, it appears difficult to make an unequivocal distinction between Boswellia carteri and B. sacra. On the other hand, Boswellia frereana (considered as a source of high-grade frankincense) shows a characteristic chromatogram and could be unambiguously distinguished from the other producing species of commercial frankincense. In a chemical point of view, Boswellia carteri and B. sacra were more especially characterized by the presence of lupeolic acid, boswellic acids and their respective O-acetyl derivatives, whereas 3-epi-lupeol was the major compound in B. frereana methanolic extracts.